Method of making mat of glass fibers



June 30 1942. P. MODIGLIANI 2,287,815

METHOD oF MAKING'MAT oFqLAss'TIBRs Filed March 3, 1939 may be="applied by vmeans vof injectors or simply "'ositedthrough lthe "force vlofgravity on the supporting surface." The-preferred embodiment Patented June' 30, 1942- UNITED STATES PATENT OFFICE Piero Modigliani, Livorno, Italy, assigner to Owens-Corning Fiberglas Corporation, Toledo, Ohio, a. corporation of Delaware Application March 3, 1939, semina. 259,704 In muy March s, 193s (Cl. lil-156) 9 Claims.

The present inventionrelates to an insulating Ufelt or mat composed `of strips of glass thread, and themethod of and apparatus for the produchrtion thereof. v a

Up to the present, insulating felts or mats ccmposed of glass ber have proven defective because they are compact and Vrelatively dense,

which density cannot beva'ried according to requirements, because of their formation from the elementary fibers or threads of glass by being deposited forcefully in close layers one on the otherv or against the other, that is, the elementary bers lie :fiat upon or against each other, without forming curls or involutions. The felt or mats thus produced were therefore poorly ventilated, and also were distributed with relatively large cavities of differentvolume extending along the length or the width of the layers, whereby sufficient regulation of the pliancy or softness "during production was impossible, particularly in the direction of depth. According to the present invention the defects are eliminated by starting with a new product of manufacture, whereby, in producing the felt, use is madeof glass fiber inthe form of ribbons or strips, about l mm. widel for example, the desired softness being attained and regulated to a better degree during manufacture thereof by the use of ribbons or strips. The method of produc-ing the insulating felt by the use of such ribbons or strips imparts to the felt the property 4of' softness'or pliancy evenly throughout thel thickness thereof, with fine and Well distributed small cavities by virtue offthe structure of the strips themselves, and a `graduated or controlled pliancycby means of a special method of coher- ``e`ntly `uniting the strips or ribbons with each other while theyare applied to forml the finished felt before and afterl they' are caused to become mingled and interconnected.

More specificallyk the4 present` method consists Serial No. 197,490. The direction of the nozvzles of the injectors may be perpendicular or else inclined in one sense or the other with respect to the movement of the depositing surface.

of beginning with ribbons or strips o'f different width andpliancy and forming felt with ribbons or strips having more orless parallel' fibers on `asuitable surface or support, which preferably is ""srnooth.' r`This*supporting surface' may be continnousor prforatefin the latter caseit is prefl erabIy'a network." vThe depositing and suppo'rtving surfacemayfbe automatically movable and guided `on 'rollersjbyfan' endless'hguide belt ar- *rangement v`I'heglass thread ribbons or strips provides for applying` the Lstrip or ribbon on a In a preferred form of carrying out the method, the air passing to the injectors is taken from a closed space below the suitably perforated `depositing surface, and the circulation is maintained by a blade wheel or centrifugal pump mounted at a suitable point in the circulatory passage, for example near the injectors.

In the apparatus for executing the method, the depositing surface enters and leaves hermetically, passing horizontally through a housing or chest, while one or more rows of ribbons or strips are introducedfrom above and are projected by means of the injectors, somewhat in the form of loops, whereby the edges of the strips or ribbons are unravelled to promote `the intermingling of the finished felt. Depositionv takes place with uniform frizzling and, curling vof `the` strips or ribbons. The width and other properties of the strips may be varied from the beginning in different ways. It is possiblethus to graduate or control the volume of the felt for a predetermined weight between limits varying from 1 to 4 and more. The resulting air cells are closed and the air remains therein, whereby the insulating properties are improved.

Such felts may find widely different uses and are to be recommended when uniformity of production and graduation or variation of the vol-` ume for a certain weightof thread are required.

TheA invention is ,describedA in the following specification with .reference 'to the 'accompany' ing drawing wherein the` construction hshownris given merely byrway oflexaxnplezh.. f

Fig. 1 isa diagrammatic, lllfsfpfictive4 view of the apparatus; a, .a Fig. 2 is a, longitu inalsectional view of, the apparatus of Figifinareducednscaler' Fig. 3 shows theuse. of; a-batteryiof strip injectors; w r

Fig.,4 shows the` blowing'l apparatus which fuses air taken from belowlthe :depositing `surfacefor blowing through the 'noazles`;`

ure 3 for feeding the respective-strips,

Fig. 5 shows the felt produced according to the new method and with the new apparatus.

Referring particularly to the gures of the drawing:

The housing l is traversed by the endless band I and is provided with the mouthpiece 2 in which different injectors are mounted. The points of entrance and exit of the circulating belt 3 are indicated at l and land are tted with packings of rubber or felt 4' and I', respectively, which render tight the air content at the point of entrance and exit respectively. Three stripsor ribbons 1,-1' and l" may be introduced in as many injector nozzles to form the felt I from the strip deposited with pronounced involutions or curls. Three injectors l, and l" are shown in Fig- In Fig. 4 is shown a circulating pipe i0 in which is mounted a fan Il, a centrifugal pump. or other apparatus, which, by pressure, forces the air into .the injectors, which is taken from a lower point of the housing l near the point at which a net Il is provided (Fig. 1), through the circulating pipe l2 constituting the straight pipe section leading to the injector nozzles.

Three guide rollers Il, Il and I 5, may be provided for the'endless belt l, which may be suitably perforated or in the form cfa net. The axis of the nozzles 0, l', I" may also be inclined toward or away from the direction of travel of the conveyor belt 3 to obtain different ccmpacting'effects of the bers.

The number of strips introduced simultaneously into the housing may vary, as well as the width thereof. By graduating or regulating the pressure in the injectors different effects of thickness and pliancy of the felt can be obtained.

The invention is described and illustrated by wa'y of example only, it being understood that it may be subject to numerous modications without departing from the scope thereof and may be applied to the handling of other articial bers of -prises depositing a plurality of strips of glass bers upon a moving surface, each strip being composed of a plurality of layers of bers, the bers of each layer being parallel and arranged in predetermined crossing relation with a contiguous layer of parallel bers and commingling the deposited bers of each of the'strips as well as the bers of strips adjacent each other.

3. The method of producing an insulating mat which'comprilses' forming a plurality of stripsof articial bers, each strip being composed of a pluralityy of layers of bers, the bers of each layer lbeing parallel and arranged in predetermined crossing relation with a contiguous layer of the bers of each layer being parallel and arranged in` predetermined crossing relation with a Acontiguous layer of parallel bers, whereby a substantially uniform commingling of bers ensues to produce a mat of uniform and regulatable texture. 5. The method of producing an insulating mat which comprises depositing with a forced draft a plurality of strips of articial bers upon a surface, each strip being composed of a plurality of layers of bers, the bers f each layer being parallel and arranged in predetermined crossing relation with a contiguous layer of parallel bers upon a surface, whereby the forced draft arranges the individual bers in the same general direction prior to the compacting thereof on said surface with the forced draft, with the simultaneously commingling of the bers upon the depositions thereof on said surface.

6. The method of producing an insulating mat which comprises dropping downwardly a plurality of strips of bers upon a moving surface with the aid of a false draft acting in the same direction and forming a part of a continuous forced circulatlng air circuit, each strip being composed of a plurality of layers of bers, the bers-of each layer being parallel and arranged in predetermined crossing relation with a contiguous layer of parallel bers, whereby an unravelling of the bers is executed by said draft preparatory to a commingling of the bers upon the deposition thereof of said surface.

7. The method of lproducing an insulating mat which comprises injecting with pneumatic force a -plurality of articial bers' next to each other upon a surface, each strip having a predeterminedwidth and being composed of a plurality of layers of bers, the ber -of each layer being parallel and arranged in'predetermined crossing relation with a contiguous layer of parallel bers, and ag'ltating the bers with said pneumatic force before and after deposition thereof, to execute a commingling thereof and the formation of a mat composed of substantially uniform convolutions.

8. The method of producing an insulating mat which comprises injecting downwardly with pneumatic force, a plurality of strips of glass bers next to each other upon an endless band, each strip having a predetermined width and being composed of a plurality of layers of bers, the bers of each layer being parallel and arranged in predetermined crossing relation with a contiguous layer of parallel bers, agitating the bers with said pneumatic force before and after the deposition thereof to execute a commingling thereof and the formation of a mat composed parallel bers, depositing a plurality of said strips next to each other ,on an endless circulating band,

. a strip of'glass bers upon a surface, each strip composed of a plurality of layers of bers, v

bei!!! of substantially uniform convolutions,land regulating the compactn'ess of the mat by varying the pneumatic force.

9. The method of producing an. insulating mat which comprises injecting downwardly with pneumatic force, a plurality of strips'of glass bers next to each other upona moving surface in a direction having a component of feed in the plane'-.-)f said moving surface, each strip being composed of a plurality of layers of bers, the bers *of each layer .being parallel and arranged in predetermined crossing relation with a contiguous layer of parallel bers and agitating the bers with said pneumatic force before and after thedeposition thereof 'to execute a commingling thereof and the formation of a mat composed ofl substantially uniform convolutions.

PIERO MODIGLIANI. 

